RT9917应用电路及参数资料

7 Channel DC/DC Converters

The RT9907 is a three channel power-supply soluTIon for digital sTIll cameras and other battery-powered devices. It integrates an asynchronous step-up and two synchronous step-down DC-DC converters. The RT9907 is targeted for applicaTIons that use two AA cells or a single lithium-ion battery.

Features

• 1 Channel Boost/Buck Selectable by SEL Pin
• 2 Selectable On/Off Sequence Set by SEQ Pin
• 4 Channels with Internal CompensaTIon
• Provide Charge Pump Voltage to Enhance NMOS Gate Driving Capability for Alkaline Battery Input
• All Power Switches Integrated
• Syn Step-Down DC/DC Converter
► Up to 95% Efficiency
► 100% (MAX) Duty Cycle
• Syn Step-Up DC/DC Converter
► Adjustable Output Voltage
► Up to 95% Efficiency
• Open LED Protection
• Transformerless Inverting Converter for CCD
• Fixed 1MHz Switching Frequency
• Compact 40-Lead WQFN Package
• RoHS Compliant and 100% Lead (Pb)-Free

Application

• Digital Still Camera
• PDA
• Portable Device

Typical Applications Circuit

For Li-ion : CH2 3.3V is from VOUT of CH1